Some eight hours after Christopher Reuther arrived in Hawai'i last year, he stepped out of his rental car at Zablan Beach Park in Nanakuli and entered a world of drugs and violence.

That much witnesses agreed on in the manslaughter trial of Less Schnabel Jr., accused of killing Reuther with a single fatal punch to the head near midnight on April 22, 2007.

They didn't agree on much else.

Yesterday, two witnesses gave diametrically opposed testimony about events leading up to that punch.

Defense witness Kristi Riverio, 30, told jurors that Reuther, 34, was the aggressor, dropping his camera bag and advancing on Schnabel after the defendant told Reuther to stop taking photographs in the parking lot.

"You cannot tell me what for do," Riverio quoted Reuther as telling Schnabel.

Schnabel hit Reuther once and the victim fell to the ground, got up, staggered a few steps toward Schnabel, then collapsed to the ground again, according to Riverio.

She said she had walked to the beach park that night with Schnabel and Nicole Ako, a prosecution witness who gave a very different version of what happened when she testified earlier in the day.

Ako, 31, was brought to court from prison, where she is serving time for selling crystal methamphetamine, the highly addictive drug commonly known as ice.

Ako testified that she was high on ice when she walked to the beach park that night with Schnabel, 24, a friend of hers who she believed was also high on the drug.

"We got high separately," Ako told jurors.

She said Riverio was not with the pair when they walked to the park, but may have followed behind.

While she was standing with Schnabel near the restroom at the beach park, Ako said, Reuther suddenly appeared behind them and snapped a photograph of the pair, surprising and angering Schnabel.

She said she thought Reuther might be a police officer and Schnabel yelled at Reuther to "get the f--- outta here."

As Reuther walked over to his rental car, Ako said she warned him to leave the area.

"Nobody comes to the beach this late at night," Ako said she told Reuther.

"He said he was taking pictures of the Hawaiians," she said.

As Reuther was putting his camera back in the trunk of his car, Schnabel approached him, swore at him again and punched him once, Ako said.

Reuther did nothing to provoke Schnabel, the witness said.

But Riverio told the jury that Ako was nowhere near the two men when the punch was thrown. She said Ako had gone into a tent on the beach occupied by known drug users, emerging only after Reuther was on the ground.

Riverio acknowledged being a former ice user herself, but said she stopped smoking the drug after witnessing the events in the parking lot.

Another witness, Christina White-Anderson, testified that she was in a car at the parking lot but did not see the assault.

White-Anderson, who was also brought from prison to testify, said she saw Schnabel take a black bag or briefcase from the trunk of Reuther's car after the victim had fallen to the ground.

Earlier in the trial, prosecution witness Harold Kaeo testified that he also tried to tell Reuther that the beach was a dangerous place to be at night.

Kaeo said he witnessed Schnabel punch the victim once in the head.

Kaeo was brought from prison to testify because he was arrested after refusing to appear as a witness in the case.

Kaeo described Reuther as a friendly man who was "maybe too friendly" for the situation he had placed himself in that night.

Kaeo also said Reuther smoked a joint of marijuana with Kaeo and six of his friends before walking out to the parking lot and encountering Schnabel.

But Chief Medical Examiner Kanthi De Alwis testified yesterday that toxicology tests of Reuther's remains were negative for any drugs, including marijuana.

De Alwis said Reuther died of injuries caused by "assaultive blunt force trauma to the head."

Reuther came to Hawai'i from his home in North Carolina to visit the William S. Richardson School of Law, where he had been offered a partial scholarship in the environmental law program.

Closing arguments in the trial, which began Monday, are expected to be delivered today.